public class Example4_10 {
   public static void main(String args[]) {
     Lader.下底 = 100;   //Lader的字节码被加载到内存，通过类名操作类变量
     Lader laderOne = new Lader();
     Lader laderTwo = new Lader();
     laderOne.设置上底(28);
     laderTwo.设置下底(66);
     System.out.println("laderOne的上底:"+laderOne.获取上底());
     System.out.println("laderOne的下底:"+laderOne.获取下底());
     System.out.println("laderTwo的上底:"+laderTwo.获取上底());
     System.out.println("laderTwo的下底:"+laderTwo.获取下底());
   }
}
